<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
    <script>
        var str;
        str="hellow"
        var st1='abc'
        st2='123'
        console.log(str.length)
        console.log(str.charAt(5))
        console.log(str.indexOf('l'))
        console.log(str.lastIndexOf('l'))
        console.log(str.includes("w"))
        console.log(st1.concat(st2))
    </script>
</body>
</html>